Biology - a science of exception, Biology

BIOLOGY - A SCIENCE OF EXCEPTION -

Some common examples to prove it are -

1.       Embryos of dicot plants have 2 cotyledons but in cuscuta (Dodder plant or amer bel or Akash bel) cotyledons are absent.

2.       Nucleus generally present in all cells except R.B.C. of mammals (in camel & lama present), sieve tubes of phloem of plants.

3.       DNA present in all animal viruses except influenza virus, polio virus, reo virus in which RNA present.

4.       RNA present in all plant viruses except cauliflower mosaic virus in which DNA present.

5.       In human 206 bones present, in human having 6 fingers in one hand 209 bones present.

6.       In birds urinnary bladder absent but present in ostrich.

7.       Kangaroo rat never drinks water in life.

8.       DNA is double strandded but in fx 174 bacteriophage single stranded DNA present.

9.       RNA is single strended but in wound tumour virus & reo virus it is double stranded. 

10.     Sexual reproduction usually occurs at puberty but in Ambyostoma's axolotal larva, it occurs at larval stage. This process is paedeogenesis and stage is neotany.

11.     Blood of all vertebrtes is red but in corcharinus (shark) it is colour less.

12.     Mammals are viviparous while Platypus, Echidna are oviparous & Kangroos or marsupials (having marsupium ponch) are ovo-viviparous.

13.     Fishes usually respire by gills but in Protopterus, Lepidosiren, Ceratodus lungs present (Dipnoi).

14.     Heart of all reptiles is incomplete 4 chambered but in crocodelia 4 chambered.

15.     In pisces heart is 2 chambered but in dipnoi 3 chambered.

16.     Mostly birds fly except ostrich, kiwi & penguine.

17.     Mammals do not fly except bat & lemur.

18.     Usually young ones are produced from zygotes while dron (male) of honey bee are formed from unfertilized egg by parthenogenesis. Dron is not having father but forefather (Nana) is present.

19.     Chromosomes number in diseased human may be 45 or 47.

20.     Femur is largest bone of human body while stapes is smallest bone.

Posted Date: 10/8/2012 4:22:14 AM | Location : United States







Related Discussions:- Biology - a science of exception, Assignment Help, Ask Question on Biology - a science of exception, Get Answer, Expert's Help, Biology - a science of exception Discussions

Write discussion on Biology - a science of exception
Your posts are moderated
Related Questions
Energy Allowance: Energy Allowance: The  patient's requirement for  energy  varies with the physical activity and physiological condition. For instance, consider a person con

Human anatomy: Human anatomy is a branch of biology which, with deals with human physiology and biochemistry. It is mainly concerned with the scientific study of the internal stru

Define about the Polyphenols? We now come to a group of compounds, which were until recently considered to adversely influence nutrient absorption or giving colour to foods e.g

Michael eats steak & cheese sub sandwiches every day of the week. Explain the types of fats that are found in steak & cheese subs and the properties of each type. Jillian eats

Explain Simple Staining Technique? Here single staining agent is used to determine the size, shape and arrangement of bacterial cells. It is simple and easy to perform. Dried s

Autophagic intracellular digestion is the cellular internal digestion of waste and residual materials. In general it is completed by lysosomes. Autophagic intracellular digestio

What is the genetic condition in which the heterozygous individual has different phenotype from the homozygous individual? This situation is called lack of dominance and it can

Q. What are the functional divisions of the nervous system? Functionally the nervous system can be divided into the visceral nervous system and somatic nervous system. The s

Intracellular digestion, or cellular digestion, is the breaking in the interior of the cell of big molecules coming from outside or even from the own cell metabolism into smaller m

Members belonging to different species refrain from mating because of the behavioural differences between them. Such behavioural differences usually centre around specific courtshi